Wireless communications systems such as mobile phones aim to enable communication “anytime and anywhere” without interruption, and have developed to support the expansion of communication areas and handoff technology between base stations.
Recently, the data amount being exchanged by a single user has been rapidly increasing, such as E-mails with photographic or moving image files attached, and motion picture of Video phones for example. Wireless communication systems are required to enable further enhancement of maximum data throughput.
Also, new wireless communications systems with lower terminal mobility but higher data throughput (close to cable network level), such as Wireless LAN or WiMAX and the like, are now appearing. Thus, there is a pressing need to achieve balanced mobility and higher data throughput for future mobile phone systems.